Electron-emitting devices include such as field emission electron-emitting devices and surface conduction electron-emitting devices. As disclosed in Patent Documents 1 to 3, there are some cases where a surface conduction electron-emitting device is performed a process referred to as “activation”. “Activation” process is a process for forming an electroconductive film (typically a carbon film) in a gap between a pair of electroconductive films and on the electroconductive films adjacent to the gap. FIG. 21 is a schematic sectional view of an electron-emitting device disclosed in Patent Documents 3 and 4. In FIG. 21, reference numeral 1 denotes a substrate, reference symbols 4a and 4b denote electroconductive thin films, reference numerals 7 and 8 denote first and second gaps, respectively, reference symbols 21a and 21b denote carbon films, and reference numeral 22 denotes a concave formed in the substrate 1.
An image display apparatus can be formed by opposing a substrate provided with an electron source having a plurality of such electron-emitting devices arranged thereon to a substrate provided with a phosphor film formed of a phosphor or the like and by maintaining vacuum inside.    [Patent Document 1] JP 2000-251642 A    [Patent Document 2] JP 2000-251643 A    [Patent Document 3] JP 2000-231872 A    [Patent Document 4] U.S. Pat. No. 6,380,665